STEM CELL RESEARCH IS NOW ON A FAST TRACK BECAUSE OF NEW DEVELOPMENTS

Stem-cell research took a great leap forward in 1998, when two independent research groups, led by Dr. James Thomson of the University of Wisconsin, Madison, and Dr. John Gearhart of Johns Hopkins University, reported success in growing human stem cells in culture. Blood stem cells (hematopoietic cells) reside in bone marrow and continuously produce a variety of blood and immune system cells. Mesenchymal stem cells are the source of new bone, cartilage, and connective tissue cells. Neuronal stem cells produce a variety of nervous system tissue, mostly during early embryonic development but, as we are beginning to learn, later in life as well. Also on the distant horizon lies the possibility of new cardiac tissue for heart attack victims, replacement blood and marrow cells for those who have undergone chemotherapy or radiation therapy for cancer, new skin tissue for burn victims, bone for those suffering from severe fractures or osteoporosis, and so on. But Thomson's use of spare human embryos provided by the University of Wisconsin's infertility clinic would be a direct violation of the existing ban on federally funded human embryo research.

After years of searching, and at times almost giving up in despair, Dr. Shinya Yamanaka of Japan may have found an alternative just this year(2007). He has successfully turned adult skin cells into the equivalent of human embryonic stem cells without using an actual embryo. Dr. Yamanaka is widely credited with being the first to hit on the idea of reprogramming adult cells to behave as stem cells. The crux of his idea was to add genes called master regulators to the skin cells’ chromosomes. These genes can change the cell’s behavior by turning other genes on and off. No one thought before of making stem cells this way. It is a totally new direction.  One challenge was figuring out which genes would re-program adult cells. With hundreds of candidate genes, the number of possible combinations was almost infinite.

He was still able to reprogram cells, and with a much lower incidence of cancer that is often produced. Yamanaka also set up a commercial collaboration between his university and a private company to use stem cells right away in laboratory research for creating new and more powerful medicines. How far we go in the future is a dizzying prospect. Everything so far seems to indicate incredible and unbelievable progress, now that we know some of the first keys.